6q12 and 11p14 variants are associated with postnatal exhaled nitric oxide levels and respiratory symptoms

TOLLIP and MUC5B modulate the effect of ambient NO2 on respiratory symptoms in infancy

BACKGROUND

Current knowledge suggests that the gene region containing MUC5B and TOLLIP plays a role in airway defence and airway inflammation, and hence respiratory disease. It is also known that exposure to air pollution increases susceptibility to respiratory disease. We aimed to study whether the effect of air pollutants on the immune response and respiratory symptoms in infants may be modified by polymorphisms in MUC5B and TOLLIP genes.

METHODS

359 healthy term infants from the prospective Basel-Bern Infant Lung Development (BILD) birth cohort were included in the study. The main outcome was the score of weekly assessed respiratory symptoms in the first year of life. Using the candidate gene approach, we selected 10 single nucleotide polymorphisms (SNPs) from the MUC5B and TOLLIP regions. Nitrogen dioxide (NO2) and particulate matter ≤10 μm in aerodynamic diameter (PM10) exposure was estimated on a weekly basis. We used generalised additive mixed models adjusted for known covariates. To validate our results in vitro, cells from a lung epithelial cell line were downregulated in TOLLIP expression and exposed to diesel particulate matter (DPM) and polyinosinic-polycytidylic acid.

RESULTS

Significant interaction was observed between modelled air pollution (weekly NO2 exposure) and 5 SNPs within MUC5B and TOLLIP genes regarding respiratory symptoms as outcome: E.g., infants carrying minor alleles of rs5744034, rs3793965 and rs3750920 (all TOLLIP) had an increased risk of respiratory symptoms with increasing NO2 exposure. In vitro experiments showed that cells downregulated for TOLLIP react differently to environmental pollutant exposure with DPM and viral stimulation.

CONCLUSION

Our findings suggest that the effect of air pollution on respiratory symptoms in infancy may be influenced by the genotype of specific SNPs from the MUC5B and TOLLIP regions. For validation of the findings, we provided in vitro evidence for the interaction of TOLLIP with air pollution.

Mediators linking obesity to childhood asthma

BACKGROUND

Obesity and asthma are highly associated, but the mechanisms underlying the association remain unknown. We examined five mediators linking obesity with childhood asthma: (1) pulmonary function impairment, (2) airway inflammation, (3) physical fitness, (4) sleep-disordered breathing (SDB), and (5) early puberty.

METHODS

A Mendelian randomization (MR) study with mediation analysis of data obtained from 5965 children as part of the Taiwan Children Health Study. Observational analysis, MR two-stage least-squares method, and MR sensitivity analysis were carried out to investigate each causal pathway. Prospective cohort analyses were used to strengthen the findings.

RESULTS

The increased asthma risk associated with obesity was found to be mostly mediated through impaired pulmonary function, low physical fitness, and early puberty. In the MR analysis, body mass index was negatively associated with FEV1/FVC and physical fitness index (β = -2.17 and -0.71; 95% CI, -3.92 to -0.42 and -1.30 to -0.13, respectively) and positively associated with early puberty (OR, 1.09; 95% CI, 1.02-1.17). High FEV1/FVC and physical fitness index reduced asthma risk (OR, 0.98 and 0.93; 95% CI, 0.97-0.99 and 0.88-0.98, respectively), whereas SDB and early puberty increased the risk of asthma (OR, 1.03 and 1.22; 95% CI, 1.01-1.05 and 1.05-1.42, respectively). Temporal causality was strengthened in prospective cohort analyses. The three main mediators were low physical fitness, impaired pulmonary function, and early puberty, with mediation proportions of 73.76%, 61.63%, and 27.66%, respectively.

CONCLUSIONS

Interventions promoting physical fitness and pulmonary function might effectively reduce obesity-induced asthma risk.

Correlation of EYS polymorphisms with lumbar disc herniation risk among Han Chinese population

BACKGROUND

Lumbar disc herniation (LDH) is a common spinal disease in clinical practice. Once lumbar disc herniation occurs, it seriously reduces patient's quality of life. The EYS (eyes shut homolog) was discovered in recent years and it may be related to lumbar disc herniation. So we conducted a case-control study to explore the relationship between EYS polymorphism and lumbar disc herniation risk.

METHODS

We selected 5 single-nucleotide polymorphisms (SNPs) of EYS gene in a case-control study with 508 cases and 508 healthy controls to evaluate the relatedness by using genetic model, haplotype, and stratification analysis.

RESULTS

We found that the minor alleles of rs62413038 (OR = 1.21, 95%CI: 1.01-1.43, p = .036) and rs9450607 (OR = 1.26, 95% CI: 1.05-1.53, p = .016) were associated with an increased risk of lumbar disc herniation in the allelic model analysis. In the genotypic model analysis, rs62413038 displayed a significantly increased risk of lumbar disc herniation in log-additive models (OR = 1.20, 95% CI: 1.01-1.43, p = .039). While the rs9450607 was also obviously associated with an increased lumbar disc herniation risk in recessive (OR = 1.98, 95% CI: 1.24-3.13, p = .004) and log-additive models (OR = 1.27, 95% CI: 1.05-1.55, p = .014). In addition, in the haplotype analyses of the SNPs, we found that the "CGGA" haplotype of rs1482456, rs9342097, rs9450607, and rs7757884 was associated with lumbar disc herniation. (OR = 0.52, 95% CI: 0.30-0.89, p = .017).

CONCLUSION

These results suggest that EYS polymorphism may be associated with lumbar disc herniation among Han Chinese population. It also opens up a new exploration direction for the etiology of lumbar disc herniation.

Atopic dermatitis: Interaction between genetic variants of GSTP1, TNF, TLR2, and TLR4 and air pollution in early life

BACKGROUND

Associations between traffic-related air pollution (TRAP) and childhood atopic dermatitis (AD) remain inconsistent, possibly due to unexplored gene-environment interactions. The aim of this study was to examine whether a potential effect of TRAP on AD prevalence in children is modified by selected single nucleotide polymorphisms (SNPs) related to oxidative stress and inflammation.

METHODS

Doctor-diagnosed AD up to age 2 years and at 7-8 years, as well as AD symptoms up to age 2 years, was assessed using parental-reported questionnaires in six birth cohorts (N = 5685). Associations of nitrogen dioxide (NO₂ ) estimated at the home address of each child at birth and nine SNPs within the GSTP1, TNF, TLR2, or TLR4 genes with AD were examined. Weighted genetic risk scores (GRS) were calculated from the above SNPs and used to estimate combined marginal genetic effects of oxidative stress and inflammation on AD and its interaction with TRAP.

RESULTS

GRS was associated with childhood AD and modified the association between NO₂ and doctor-diagnosed AD up to the age of 2 years (P(interaction) = .029). This interaction was mainly driven by a higher susceptibility to air pollution in TNF rs1800629 minor allele (A) carriers. TRAP was not associated with the prevalence of AD in the general population.

CONCLUSIONS

The marginal genetic association of a weighted GRS from GSTP1, TNF, TLR2, and TLR4SNPs and its interaction with air pollution supports the role of oxidative stress and inflammation in AD.